1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/nfs/nfs2xdr.c
4 *
5 * XDR functions to encode/decode NFS RPC arguments and results.
6 *
7 * Copyright (C) 1992, 1993, 1994 Rick Sladkey
8 * Copyright (C) 1996 Olaf Kirch
9 * 04 Aug 1998 Ion Badulescu <ionut@cs.columbia.edu>
10 * FIFO's need special handling in NFSv2
11 */
12
13#include <linux/param.h>
14#include <linux/time.h>
15#include <linux/mm.h>
16#include <linux/errno.h>
17#include <linux/string.h>
18#include <linux/in.h>
19#include <linux/pagemap.h>
20#include <linux/proc_fs.h>
21#include <linux/sunrpc/clnt.h>
22#include <linux/nfs.h>
23#include <linux/nfs2.h>
24#include <linux/nfs_fs.h>
25#include <linux/nfs_common.h>
26#include "internal.h"
27#include "nfstrace.h"
28
29#define NFSDBG_FACILITY NFSDBG_XDR
30
31/*
32 * Declare the space requirements for NFS arguments and replies as
33 * number of 32bit-words
34 */
35#define NFS_pagepad_sz (1) /* Page padding */
36#define NFS_fhandle_sz (8)
37#define NFS_sattr_sz (8)
38#define NFS_filename_sz (1+(NFS2_MAXNAMLEN>>2))
39#define NFS_path_sz (1+(NFS2_MAXPATHLEN>>2))
40#define NFS_fattr_sz (17)
41#define NFS_info_sz (5)
42#define NFS_entry_sz (NFS_filename_sz+3)
43
44#define NFS_diropargs_sz (NFS_fhandle_sz+NFS_filename_sz)
45#define NFS_removeargs_sz (NFS_fhandle_sz+NFS_filename_sz)
46#define NFS_sattrargs_sz (NFS_fhandle_sz+NFS_sattr_sz)
47#define NFS_readlinkargs_sz (NFS_fhandle_sz)
48#define NFS_readargs_sz (NFS_fhandle_sz+3)
49#define NFS_writeargs_sz (NFS_fhandle_sz+4)
50#define NFS_createargs_sz (NFS_diropargs_sz+NFS_sattr_sz)
51#define NFS_renameargs_sz (NFS_diropargs_sz+NFS_diropargs_sz)
52#define NFS_linkargs_sz (NFS_fhandle_sz+NFS_diropargs_sz)
53#define NFS_symlinkargs_sz (NFS_diropargs_sz+1+NFS_sattr_sz)
54#define NFS_readdirargs_sz (NFS_fhandle_sz+2)
55
56#define NFS_attrstat_sz (1+NFS_fattr_sz)
57#define NFS_diropres_sz (1+NFS_fhandle_sz+NFS_fattr_sz)
58#define NFS_readlinkres_sz (2+NFS_pagepad_sz)
59#define NFS_readres_sz (1+NFS_fattr_sz+1+NFS_pagepad_sz)
60#define NFS_writeres_sz (NFS_attrstat_sz)
61#define NFS_stat_sz (1)
62#define NFS_readdirres_sz (1+NFS_pagepad_sz)
63#define NFS_statfsres_sz (1+NFS_info_sz)
64
65/*
66 * Encode/decode NFSv2 basic data types
67 *
68 * Basic NFSv2 data types are defined in section 2.3 of RFC 1094:
69 * "NFS: Network File System Protocol Specification".
70 *
71 * Not all basic data types have their own encoding and decoding
72 * functions. For run-time efficiency, some data types are encoded
73 * or decoded inline.
74 */
75
76static struct user_namespace *rpc_userns(const struct rpc_clnt *clnt)
77{
78 if (clnt && clnt->cl_cred)
79 return clnt->cl_cred->user_ns;
80 return &init_user_ns;
81}
82
83static struct user_namespace *rpc_rqst_userns(const struct rpc_rqst *rqstp)
84{
85 if (rqstp->rq_task)
86 return rpc_userns(clnt: rqstp->rq_task->tk_client);
87 return &init_user_ns;
88}
89
90/*
91 * typedef opaque nfsdata<>;
92 */
93static int decode_nfsdata(struct xdr_stream *xdr, struct nfs_pgio_res *result)
94{
95 u32 recvd, count;
96 __be32 *p;
97
98 p = xdr_inline_decode(xdr, nbytes: 4);
99 if (unlikely(!p))
100 return -EIO;
101 count = be32_to_cpup(p);
102 recvd = xdr_read_pages(xdr, len: count);
103 if (unlikely(count > recvd))
104 goto out_cheating;
105out:
106 result->eof = 0; /* NFSv2 does not pass EOF flag on the wire. */
107 result->count = count;
108 return count;
109out_cheating:
110 dprintk("NFS: server cheating in read result: "
111 "count %u > recvd %u\n", count, recvd);
112 count = recvd;
113 goto out;
114}
115
116/*
117 * enum stat {
118 * NFS_OK = 0,
119 * NFSERR_PERM = 1,
120 * NFSERR_NOENT = 2,
121 * NFSERR_IO = 5,
122 * NFSERR_NXIO = 6,
123 * NFSERR_ACCES = 13,
124 * NFSERR_EXIST = 17,
125 * NFSERR_NODEV = 19,
126 * NFSERR_NOTDIR = 20,
127 * NFSERR_ISDIR = 21,
128 * NFSERR_FBIG = 27,
129 * NFSERR_NOSPC = 28,
130 * NFSERR_ROFS = 30,
131 * NFSERR_NAMETOOLONG = 63,
132 * NFSERR_NOTEMPTY = 66,
133 * NFSERR_DQUOT = 69,
134 * NFSERR_STALE = 70,
135 * NFSERR_WFLUSH = 99
136 * };
137 */
138static int decode_stat(struct xdr_stream *xdr, enum nfs_stat *status)
139{
140 __be32 *p;
141
142 p = xdr_inline_decode(xdr, nbytes: 4);
143 if (unlikely(!p))
144 return -EIO;
145 if (unlikely(*p != cpu_to_be32(NFS_OK)))
146 goto out_status;
147 *status = 0;
148 return 0;
149out_status:
150 *status = be32_to_cpup(p);
151 trace_nfs_xdr_status(xdr, error: (int)*status);
152 return 0;
153}
154
155/*
156 * 2.3.2. ftype
157 *
158 * enum ftype {
159 * NFNON = 0,
160 * NFREG = 1,
161 * NFDIR = 2,
162 * NFBLK = 3,
163 * NFCHR = 4,
164 * NFLNK = 5
165 * };
166 *
167 */
168static __be32 *xdr_decode_ftype(__be32 *p, u32 *type)
169{
170 *type = be32_to_cpup(p: p++);
171 if (unlikely(*type > NF2FIFO))
172 *type = NFBAD;
173 return p;
174}
175
176/*
177 * 2.3.3. fhandle
178 *
179 * typedef opaque fhandle[FHSIZE];
180 */
181static void encode_fhandle(struct xdr_stream *xdr, const struct nfs_fh *fh)
182{
183 __be32 *p;
184
185 p = xdr_reserve_space(xdr, NFS2_FHSIZE);
186 memcpy(p, fh->data, NFS2_FHSIZE);
187}
188
189static int decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
190{
191 __be32 *p;
192
193 p = xdr_inline_decode(xdr, NFS2_FHSIZE);
194 if (unlikely(!p))
195 return -EIO;
196 fh->size = NFS2_FHSIZE;
197 memcpy(fh->data, p, NFS2_FHSIZE);
198 return 0;
199}
200
201/*
202 * 2.3.4. timeval
203 *
204 * struct timeval {
205 * unsigned int seconds;
206 * unsigned int useconds;
207 * };
208 */
209static __be32 *xdr_encode_time(__be32 *p, const struct timespec64 *timep)
210{
211 *p++ = cpu_to_be32((u32)timep->tv_sec);
212 if (timep->tv_nsec != 0)
213 *p++ = cpu_to_be32(timep->tv_nsec / NSEC_PER_USEC);
214 else
215 *p++ = cpu_to_be32(0);
216 return p;
217}
218
219/*
220 * Passing the invalid value useconds=1000000 is a Sun convention for
221 * "set to current server time". It's needed to make permissions checks
222 * for the "touch" program across v2 mounts to Solaris and Irix servers
223 * work correctly. See description of sattr in section 6.1 of "NFS
224 * Illustrated" by Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5.
225 */
226static __be32 *xdr_encode_current_server_time(__be32 *p,
227 const struct timespec64 *timep)
228{
229 *p++ = cpu_to_be32(timep->tv_sec);
230 *p++ = cpu_to_be32(1000000);
231 return p;
232}
233
234static __be32 *xdr_decode_time(__be32 *p, struct timespec64 *timep)
235{
236 timep->tv_sec = be32_to_cpup(p: p++);
237 timep->tv_nsec = be32_to_cpup(p: p++) * NSEC_PER_USEC;
238 return p;
239}
240
241/*
242 * 2.3.5. fattr
243 *
244 * struct fattr {
245 * ftype type;
246 * unsigned int mode;
247 * unsigned int nlink;
248 * unsigned int uid;
249 * unsigned int gid;
250 * unsigned int size;
251 * unsigned int blocksize;
252 * unsigned int rdev;
253 * unsigned int blocks;
254 * unsigned int fsid;
255 * unsigned int fileid;
256 * timeval atime;
257 * timeval mtime;
258 * timeval ctime;
259 * };
260 *
261 */
262static int decode_fattr(struct xdr_stream *xdr, struct nfs_fattr *fattr,
263 struct user_namespace *userns)
264{
265 u32 rdev, type;
266 __be32 *p;
267
268 p = xdr_inline_decode(xdr, NFS_fattr_sz << 2);
269 if (unlikely(!p))
270 return -EIO;
271
272 fattr->valid |= NFS_ATTR_FATTR_V2;
273
274 p = xdr_decode_ftype(p, type: &type);
275
276 fattr->mode = be32_to_cpup(p: p++);
277 fattr->nlink = be32_to_cpup(p: p++);
278 fattr->uid = make_kuid(from: userns, be32_to_cpup(p: p++));
279 if (!uid_valid(uid: fattr->uid))
280 goto out_uid;
281 fattr->gid = make_kgid(from: userns, be32_to_cpup(p: p++));
282 if (!gid_valid(gid: fattr->gid))
283 goto out_gid;
284
285 fattr->size = be32_to_cpup(p: p++);
286 fattr->du.nfs2.blocksize = be32_to_cpup(p: p++);
287
288 rdev = be32_to_cpup(p: p++);
289 fattr->rdev = new_decode_dev(dev: rdev);
290 if (type == (u32)NFCHR && rdev == (u32)NFS2_FIFO_DEV) {
291 fattr->mode = (fattr->mode & ~S_IFMT) | S_IFIFO;
292 fattr->rdev = 0;
293 }
294
295 fattr->du.nfs2.blocks = be32_to_cpup(p: p++);
296 fattr->fsid.major = be32_to_cpup(p: p++);
297 fattr->fsid.minor = 0;
298 fattr->fileid = be32_to_cpup(p: p++);
299
300 p = xdr_decode_time(p, timep: &fattr->atime);
301 p = xdr_decode_time(p, timep: &fattr->mtime);
302 xdr_decode_time(p, timep: &fattr->ctime);
303 fattr->change_attr = nfs_timespec_to_change_attr(ts: &fattr->ctime);
304
305 return 0;
306out_uid:
307 dprintk("NFS: returned invalid uid\n");
308 return -EINVAL;
309out_gid:
310 dprintk("NFS: returned invalid gid\n");
311 return -EINVAL;
312}
313
314/*
315 * 2.3.6. sattr
316 *
317 * struct sattr {
318 * unsigned int mode;
319 * unsigned int uid;
320 * unsigned int gid;
321 * unsigned int size;
322 * timeval atime;
323 * timeval mtime;
324 * };
325 */
326
327#define NFS2_SATTR_NOT_SET (0xffffffff)
328
329static __be32 *xdr_time_not_set(__be32 *p)
330{
331 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
332 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
333 return p;
334}
335
336static void encode_sattr(struct xdr_stream *xdr, const struct iattr *attr,
337 struct user_namespace *userns)
338{
339 __be32 *p;
340
341 p = xdr_reserve_space(xdr, NFS_sattr_sz << 2);
342
343 if (attr->ia_valid & ATTR_MODE)
344 *p++ = cpu_to_be32(attr->ia_mode);
345 else
346 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
347 if (attr->ia_valid & ATTR_UID)
348 *p++ = cpu_to_be32(from_kuid_munged(userns, attr->ia_uid));
349 else
350 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
351 if (attr->ia_valid & ATTR_GID)
352 *p++ = cpu_to_be32(from_kgid_munged(userns, attr->ia_gid));
353 else
354 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
355 if (attr->ia_valid & ATTR_SIZE)
356 *p++ = cpu_to_be32((u32)attr->ia_size);
357 else
358 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
359
360 if (attr->ia_valid & ATTR_ATIME_SET)
361 p = xdr_encode_time(p, timep: &attr->ia_atime);
362 else if (attr->ia_valid & ATTR_ATIME)
363 p = xdr_encode_current_server_time(p, timep: &attr->ia_atime);
364 else
365 p = xdr_time_not_set(p);
366 if (attr->ia_valid & ATTR_MTIME_SET)
367 xdr_encode_time(p, timep: &attr->ia_mtime);
368 else if (attr->ia_valid & ATTR_MTIME)
369 xdr_encode_current_server_time(p, timep: &attr->ia_mtime);
370 else
371 xdr_time_not_set(p);
372}
373
374/*
375 * 2.3.7. filename
376 *
377 * typedef string filename<MAXNAMLEN>;
378 */
379static void encode_filename(struct xdr_stream *xdr,
380 const char *name, u32 length)
381{
382 __be32 *p;
383
384 WARN_ON_ONCE(length > NFS2_MAXNAMLEN);
385 p = xdr_reserve_space(xdr, nbytes: 4 + length);
386 xdr_encode_opaque(p, ptr: name, len: length);
387}
388
389static int decode_filename_inline(struct xdr_stream *xdr,
390 const char **name, u32 *length)
391{
392 __be32 *p;
393 u32 count;
394
395 p = xdr_inline_decode(xdr, nbytes: 4);
396 if (unlikely(!p))
397 return -EIO;
398 count = be32_to_cpup(p);
399 if (count > NFS3_MAXNAMLEN)
400 goto out_nametoolong;
401 p = xdr_inline_decode(xdr, nbytes: count);
402 if (unlikely(!p))
403 return -EIO;
404 *name = (const char *)p;
405 *length = count;
406 return 0;
407out_nametoolong:
408 dprintk("NFS: returned filename too long: %u\n", count);
409 return -ENAMETOOLONG;
410}
411
412/*
413 * 2.3.8. path
414 *
415 * typedef string path<MAXPATHLEN>;
416 */
417static void encode_path(struct xdr_stream *xdr, struct page **pages, u32 length)
418{
419 __be32 *p;
420
421 p = xdr_reserve_space(xdr, nbytes: 4);
422 *p = cpu_to_be32(length);
423 xdr_write_pages(xdr, pages, base: 0, len: length);
424}
425
426static int decode_path(struct xdr_stream *xdr)
427{
428 u32 length, recvd;
429 __be32 *p;
430
431 p = xdr_inline_decode(xdr, nbytes: 4);
432 if (unlikely(!p))
433 return -EIO;
434 length = be32_to_cpup(p);
435 if (unlikely(length >= xdr->buf->page_len || length > NFS_MAXPATHLEN))
436 goto out_size;
437 recvd = xdr_read_pages(xdr, len: length);
438 if (unlikely(length > recvd))
439 goto out_cheating;
440 xdr_terminate_string(xdr->buf, length);
441 return 0;
442out_size:
443 dprintk("NFS: returned pathname too long: %u\n", length);
444 return -ENAMETOOLONG;
445out_cheating:
446 dprintk("NFS: server cheating in pathname result: "
447 "length %u > received %u\n", length, recvd);
448 return -EIO;
449}
450
451/*
452 * 2.3.9. attrstat
453 *
454 * union attrstat switch (stat status) {
455 * case NFS_OK:
456 * fattr attributes;
457 * default:
458 * void;
459 * };
460 */
461static int decode_attrstat(struct xdr_stream *xdr, struct nfs_fattr *result,
462 __u32 *op_status,
463 struct user_namespace *userns)
464{
465 enum nfs_stat status;
466 int error;
467
468 error = decode_stat(xdr, status: &status);
469 if (unlikely(error))
470 goto out;
471 if (op_status)
472 *op_status = status;
473 if (status != NFS_OK)
474 goto out_default;
475 error = decode_fattr(xdr, fattr: result, userns);
476out:
477 return error;
478out_default:
479 return nfs_stat_to_errno(status);
480}
481
482/*
483 * 2.3.10. diropargs
484 *
485 * struct diropargs {
486 * fhandle dir;
487 * filename name;
488 * };
489 */
490static void encode_diropargs(struct xdr_stream *xdr, const struct nfs_fh *fh,
491 const char *name, u32 length)
492{
493 encode_fhandle(xdr, fh);
494 encode_filename(xdr, name, length);
495}
496
497/*
498 * 2.3.11. diropres
499 *
500 * union diropres switch (stat status) {
501 * case NFS_OK:
502 * struct {
503 * fhandle file;
504 * fattr attributes;
505 * } diropok;
506 * default:
507 * void;
508 * };
509 */
510static int decode_diropok(struct xdr_stream *xdr, struct nfs_diropok *result,
511 struct user_namespace *userns)
512{
513 int error;
514
515 error = decode_fhandle(xdr, fh: result->fh);
516 if (unlikely(error))
517 goto out;
518 error = decode_fattr(xdr, fattr: result->fattr, userns);
519out:
520 return error;
521}
522
523static int decode_diropres(struct xdr_stream *xdr, struct nfs_diropok *result,
524 struct user_namespace *userns)
525{
526 enum nfs_stat status;
527 int error;
528
529 error = decode_stat(xdr, status: &status);
530 if (unlikely(error))
531 goto out;
532 if (status != NFS_OK)
533 goto out_default;
534 error = decode_diropok(xdr, result, userns);
535out:
536 return error;
537out_default:
538 return nfs_stat_to_errno(status);
539}
540
541
542/*
543 * NFSv2 XDR encode functions
544 *
545 * NFSv2 argument types are defined in section 2.2 of RFC 1094:
546 * "NFS: Network File System Protocol Specification".
547 */
548
549static void nfs2_xdr_enc_fhandle(struct rpc_rqst *req,
550 struct xdr_stream *xdr,
551 const void *data)
552{
553 const struct nfs_fh *fh = data;
554
555 encode_fhandle(xdr, fh);
556}
557
558/*
559 * 2.2.3. sattrargs
560 *
561 * struct sattrargs {
562 * fhandle file;
563 * sattr attributes;
564 * };
565 */
566static void nfs2_xdr_enc_sattrargs(struct rpc_rqst *req,
567 struct xdr_stream *xdr,
568 const void *data)
569{
570 const struct nfs_sattrargs *args = data;
571
572 encode_fhandle(xdr, fh: args->fh);
573 encode_sattr(xdr, attr: args->sattr, userns: rpc_rqst_userns(rqstp: req));
574}
575
576static void nfs2_xdr_enc_diropargs(struct rpc_rqst *req,
577 struct xdr_stream *xdr,
578 const void *data)
579{
580 const struct nfs_diropargs *args = data;
581
582 encode_diropargs(xdr, fh: args->fh, name: args->name, length: args->len);
583}
584
585static void nfs2_xdr_enc_readlinkargs(struct rpc_rqst *req,
586 struct xdr_stream *xdr,
587 const void *data)
588{
589 const struct nfs_readlinkargs *args = data;
590
591 encode_fhandle(xdr, fh: args->fh);
592 rpc_prepare_reply_pages(req, pages: args->pages, base: args->pgbase, len: args->pglen,
593 NFS_readlinkres_sz - NFS_pagepad_sz);
594}
595
596/*
597 * 2.2.7. readargs
598 *
599 * struct readargs {
600 * fhandle file;
601 * unsigned offset;
602 * unsigned count;
603 * unsigned totalcount;
604 * };
605 */
606static void encode_readargs(struct xdr_stream *xdr,
607 const struct nfs_pgio_args *args)
608{
609 u32 offset = args->offset;
610 u32 count = args->count;
611 __be32 *p;
612
613 encode_fhandle(xdr, fh: args->fh);
614
615 p = xdr_reserve_space(xdr, nbytes: 4 + 4 + 4);
616 *p++ = cpu_to_be32(offset);
617 *p++ = cpu_to_be32(count);
618 *p = cpu_to_be32(count);
619}
620
621static void nfs2_xdr_enc_readargs(struct rpc_rqst *req,
622 struct xdr_stream *xdr,
623 const void *data)
624{
625 const struct nfs_pgio_args *args = data;
626
627 encode_readargs(xdr, args);
628 rpc_prepare_reply_pages(req, pages: args->pages, base: args->pgbase, len: args->count,
629 NFS_readres_sz - NFS_pagepad_sz);
630 req->rq_rcv_buf.flags |= XDRBUF_READ;
631}
632
633/*
634 * 2.2.9. writeargs
635 *
636 * struct writeargs {
637 * fhandle file;
638 * unsigned beginoffset;
639 * unsigned offset;
640 * unsigned totalcount;
641 * nfsdata data;
642 * };
643 */
644static void encode_writeargs(struct xdr_stream *xdr,
645 const struct nfs_pgio_args *args)
646{
647 u32 offset = args->offset;
648 u32 count = args->count;
649 __be32 *p;
650
651 encode_fhandle(xdr, fh: args->fh);
652
653 p = xdr_reserve_space(xdr, nbytes: 4 + 4 + 4 + 4);
654 *p++ = cpu_to_be32(offset);
655 *p++ = cpu_to_be32(offset);
656 *p++ = cpu_to_be32(count);
657
658 /* nfsdata */
659 *p = cpu_to_be32(count);
660 xdr_write_pages(xdr, pages: args->pages, base: args->pgbase, len: count);
661}
662
663static void nfs2_xdr_enc_writeargs(struct rpc_rqst *req,
664 struct xdr_stream *xdr,
665 const void *data)
666{
667 const struct nfs_pgio_args *args = data;
668
669 encode_writeargs(xdr, args);
670 xdr->buf->flags |= XDRBUF_WRITE;
671}
672
673/*
674 * 2.2.10. createargs
675 *
676 * struct createargs {
677 * diropargs where;
678 * sattr attributes;
679 * };
680 */
681static void nfs2_xdr_enc_createargs(struct rpc_rqst *req,
682 struct xdr_stream *xdr,
683 const void *data)
684{
685 const struct nfs_createargs *args = data;
686
687 encode_diropargs(xdr, fh: args->fh, name: args->name, length: args->len);
688 encode_sattr(xdr, attr: args->sattr, userns: rpc_rqst_userns(rqstp: req));
689}
690
691static void nfs2_xdr_enc_removeargs(struct rpc_rqst *req,
692 struct xdr_stream *xdr,
693 const void *data)
694{
695 const struct nfs_removeargs *args = data;
696
697 encode_diropargs(xdr, fh: args->fh, name: args->name.name, length: args->name.len);
698}
699
700/*
701 * 2.2.12. renameargs
702 *
703 * struct renameargs {
704 * diropargs from;
705 * diropargs to;
706 * };
707 */
708static void nfs2_xdr_enc_renameargs(struct rpc_rqst *req,
709 struct xdr_stream *xdr,
710 const void *data)
711{
712 const struct nfs_renameargs *args = data;
713 const struct qstr *old = args->old_name;
714 const struct qstr *new = args->new_name;
715
716 encode_diropargs(xdr, fh: args->old_dir, name: old->name, length: old->len);
717 encode_diropargs(xdr, fh: args->new_dir, name: new->name, length: new->len);
718}
719
720/*
721 * 2.2.13. linkargs
722 *
723 * struct linkargs {
724 * fhandle from;
725 * diropargs to;
726 * };
727 */
728static void nfs2_xdr_enc_linkargs(struct rpc_rqst *req,
729 struct xdr_stream *xdr,
730 const void *data)
731{
732 const struct nfs_linkargs *args = data;
733
734 encode_fhandle(xdr, fh: args->fromfh);
735 encode_diropargs(xdr, fh: args->tofh, name: args->toname, length: args->tolen);
736}
737
738/*
739 * 2.2.14. symlinkargs
740 *
741 * struct symlinkargs {
742 * diropargs from;
743 * path to;
744 * sattr attributes;
745 * };
746 */
747static void nfs2_xdr_enc_symlinkargs(struct rpc_rqst *req,
748 struct xdr_stream *xdr,
749 const void *data)
750{
751 const struct nfs_symlinkargs *args = data;
752
753 encode_diropargs(xdr, fh: args->fromfh, name: args->fromname, length: args->fromlen);
754 encode_path(xdr, pages: args->pages, length: args->pathlen);
755 encode_sattr(xdr, attr: args->sattr, userns: rpc_rqst_userns(rqstp: req));
756}
757
758/*
759 * 2.2.17. readdirargs
760 *
761 * struct readdirargs {
762 * fhandle dir;
763 * nfscookie cookie;
764 * unsigned count;
765 * };
766 */
767static void encode_readdirargs(struct xdr_stream *xdr,
768 const struct nfs_readdirargs *args)
769{
770 __be32 *p;
771
772 encode_fhandle(xdr, fh: args->fh);
773
774 p = xdr_reserve_space(xdr, nbytes: 4 + 4);
775 *p++ = cpu_to_be32(args->cookie);
776 *p = cpu_to_be32(args->count);
777}
778
779static void nfs2_xdr_enc_readdirargs(struct rpc_rqst *req,
780 struct xdr_stream *xdr,
781 const void *data)
782{
783 const struct nfs_readdirargs *args = data;
784
785 encode_readdirargs(xdr, args);
786 rpc_prepare_reply_pages(req, pages: args->pages, base: 0, len: args->count,
787 NFS_readdirres_sz - NFS_pagepad_sz);
788}
789
790/*
791 * NFSv2 XDR decode functions
792 *
793 * NFSv2 result types are defined in section 2.2 of RFC 1094:
794 * "NFS: Network File System Protocol Specification".
795 */
796
797static int nfs2_xdr_dec_stat(struct rpc_rqst *req, struct xdr_stream *xdr,
798 void *__unused)
799{
800 enum nfs_stat status;
801 int error;
802
803 error = decode_stat(xdr, status: &status);
804 if (unlikely(error))
805 goto out;
806 if (status != NFS_OK)
807 goto out_default;
808out:
809 return error;
810out_default:
811 return nfs_stat_to_errno(status);
812}
813
814static int nfs2_xdr_dec_attrstat(struct rpc_rqst *req, struct xdr_stream *xdr,
815 void *result)
816{
817 return decode_attrstat(xdr, result, NULL, userns: rpc_rqst_userns(rqstp: req));
818}
819
820static int nfs2_xdr_dec_diropres(struct rpc_rqst *req, struct xdr_stream *xdr,
821 void *result)
822{
823 return decode_diropres(xdr, result, userns: rpc_rqst_userns(rqstp: req));
824}
825
826/*
827 * 2.2.6. readlinkres
828 *
829 * union readlinkres switch (stat status) {
830 * case NFS_OK:
831 * path data;
832 * default:
833 * void;
834 * };
835 */
836static int nfs2_xdr_dec_readlinkres(struct rpc_rqst *req,
837 struct xdr_stream *xdr, void *__unused)
838{
839 enum nfs_stat status;
840 int error;
841
842 error = decode_stat(xdr, status: &status);
843 if (unlikely(error))
844 goto out;
845 if (status != NFS_OK)
846 goto out_default;
847 error = decode_path(xdr);
848out:
849 return error;
850out_default:
851 return nfs_stat_to_errno(status);
852}
853
854/*
855 * 2.2.7. readres
856 *
857 * union readres switch (stat status) {
858 * case NFS_OK:
859 * fattr attributes;
860 * nfsdata data;
861 * default:
862 * void;
863 * };
864 */
865static int nfs2_xdr_dec_readres(struct rpc_rqst *req, struct xdr_stream *xdr,
866 void *data)
867{
868 struct nfs_pgio_res *result = data;
869 enum nfs_stat status;
870 int error;
871
872 error = decode_stat(xdr, status: &status);
873 if (unlikely(error))
874 goto out;
875 result->op_status = status;
876 if (status != NFS_OK)
877 goto out_default;
878 error = decode_fattr(xdr, fattr: result->fattr, userns: rpc_rqst_userns(rqstp: req));
879 if (unlikely(error))
880 goto out;
881 error = decode_nfsdata(xdr, result);
882out:
883 return error;
884out_default:
885 return nfs_stat_to_errno(status);
886}
887
888static int nfs2_xdr_dec_writeres(struct rpc_rqst *req, struct xdr_stream *xdr,
889 void *data)
890{
891 struct nfs_pgio_res *result = data;
892
893 /* All NFSv2 writes are "file sync" writes */
894 result->verf->committed = NFS_FILE_SYNC;
895 return decode_attrstat(xdr, result: result->fattr, op_status: &result->op_status,
896 userns: rpc_rqst_userns(rqstp: req));
897}
898
899/**
900 * nfs2_decode_dirent - Decode a single NFSv2 directory entry stored in
901 * the local page cache.
902 * @xdr: XDR stream where entry resides
903 * @entry: buffer to fill in with entry data
904 * @plus: boolean indicating whether this should be a readdirplus entry
905 *
906 * Returns zero if successful, otherwise a negative errno value is
907 * returned.
908 *
909 * This function is not invoked during READDIR reply decoding, but
910 * rather whenever an application invokes the getdents(2) system call
911 * on a directory already in our cache.
912 *
913 * 2.2.17. entry
914 *
915 * struct entry {
916 * unsigned fileid;
917 * filename name;
918 * nfscookie cookie;
919 * entry *nextentry;
920 * };
921 */
922int nfs2_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
923 bool plus)
924{
925 __be32 *p;
926 int error;
927
928 p = xdr_inline_decode(xdr, nbytes: 4);
929 if (unlikely(!p))
930 return -EAGAIN;
931 if (*p++ == xdr_zero) {
932 p = xdr_inline_decode(xdr, nbytes: 4);
933 if (unlikely(!p))
934 return -EAGAIN;
935 if (*p++ == xdr_zero)
936 return -EAGAIN;
937 entry->eof = 1;
938 return -EBADCOOKIE;
939 }
940
941 p = xdr_inline_decode(xdr, nbytes: 4);
942 if (unlikely(!p))
943 return -EAGAIN;
944 entry->ino = be32_to_cpup(p);
945
946 error = decode_filename_inline(xdr, name: &entry->name, length: &entry->len);
947 if (unlikely(error))
948 return error == -ENAMETOOLONG ? -ENAMETOOLONG : -EAGAIN;
949
950 /*
951 * The type (size and byte order) of nfscookie isn't defined in
952 * RFC 1094. This implementation assumes that it's an XDR uint32.
953 */
954 p = xdr_inline_decode(xdr, nbytes: 4);
955 if (unlikely(!p))
956 return -EAGAIN;
957 entry->cookie = be32_to_cpup(p);
958
959 entry->d_type = DT_UNKNOWN;
960
961 return 0;
962}
963
964/*
965 * 2.2.17. readdirres
966 *
967 * union readdirres switch (stat status) {
968 * case NFS_OK:
969 * struct {
970 * entry *entries;
971 * bool eof;
972 * } readdirok;
973 * default:
974 * void;
975 * };
976 *
977 * Read the directory contents into the page cache, but don't
978 * touch them. The actual decoding is done by nfs2_decode_dirent()
979 * during subsequent nfs_readdir() calls.
980 */
981static int decode_readdirok(struct xdr_stream *xdr)
982{
983 return xdr_read_pages(xdr, len: xdr->buf->page_len);
984}
985
986static int nfs2_xdr_dec_readdirres(struct rpc_rqst *req,
987 struct xdr_stream *xdr, void *__unused)
988{
989 enum nfs_stat status;
990 int error;
991
992 error = decode_stat(xdr, status: &status);
993 if (unlikely(error))
994 goto out;
995 if (status != NFS_OK)
996 goto out_default;
997 error = decode_readdirok(xdr);
998out:
999 return error;
1000out_default:
1001 return nfs_stat_to_errno(status);
1002}
1003
1004/*
1005 * 2.2.18. statfsres
1006 *
1007 * union statfsres (stat status) {
1008 * case NFS_OK:
1009 * struct {
1010 * unsigned tsize;
1011 * unsigned bsize;
1012 * unsigned blocks;
1013 * unsigned bfree;
1014 * unsigned bavail;
1015 * } info;
1016 * default:
1017 * void;
1018 * };
1019 */
1020static int decode_info(struct xdr_stream *xdr, struct nfs2_fsstat *result)
1021{
1022 __be32 *p;
1023
1024 p = xdr_inline_decode(xdr, NFS_info_sz << 2);
1025 if (unlikely(!p))
1026 return -EIO;
1027 result->tsize = be32_to_cpup(p: p++);
1028 result->bsize = be32_to_cpup(p: p++);
1029 result->blocks = be32_to_cpup(p: p++);
1030 result->bfree = be32_to_cpup(p: p++);
1031 result->bavail = be32_to_cpup(p);
1032 return 0;
1033}
1034
1035static int nfs2_xdr_dec_statfsres(struct rpc_rqst *req, struct xdr_stream *xdr,
1036 void *result)
1037{
1038 enum nfs_stat status;
1039 int error;
1040
1041 error = decode_stat(xdr, status: &status);
1042 if (unlikely(error))
1043 goto out;
1044 if (status != NFS_OK)
1045 goto out_default;
1046 error = decode_info(xdr, result);
1047out:
1048 return error;
1049out_default:
1050 return nfs_stat_to_errno(status);
1051}
1052
1053#define PROC(proc, argtype, restype, timer) \
1054[NFSPROC_##proc] = { \
1055 .p_proc = NFSPROC_##proc, \
1056 .p_encode = nfs2_xdr_enc_##argtype, \
1057 .p_decode = nfs2_xdr_dec_##restype, \
1058 .p_arglen = NFS_##argtype##_sz, \
1059 .p_replen = NFS_##restype##_sz, \
1060 .p_timer = timer, \
1061 .p_statidx = NFSPROC_##proc, \
1062 .p_name = #proc, \
1063 }
1064const struct rpc_procinfo nfs_procedures[] = {
1065 PROC(GETATTR, fhandle, attrstat, 1),
1066 PROC(SETATTR, sattrargs, attrstat, 0),
1067 PROC(LOOKUP, diropargs, diropres, 2),
1068 PROC(READLINK, readlinkargs, readlinkres, 3),
1069 PROC(READ, readargs, readres, 3),
1070 PROC(WRITE, writeargs, writeres, 4),
1071 PROC(CREATE, createargs, diropres, 0),
1072 PROC(REMOVE, removeargs, stat, 0),
1073 PROC(RENAME, renameargs, stat, 0),
1074 PROC(LINK, linkargs, stat, 0),
1075 PROC(SYMLINK, symlinkargs, stat, 0),
1076 PROC(MKDIR, createargs, diropres, 0),
1077 PROC(RMDIR, diropargs, stat, 0),
1078 PROC(READDIR, readdirargs, readdirres, 3),
1079 PROC(STATFS, fhandle, statfsres, 0),
1080};
1081
1082static unsigned int nfs_version2_counts[ARRAY_SIZE(nfs_procedures)];
1083const struct rpc_version nfs_version2 = {
1084 .number = 2,
1085 .nrprocs = ARRAY_SIZE(nfs_procedures),
1086 .procs = nfs_procedures,
1087 .counts = nfs_version2_counts,
1088};
1089

source code of linux/fs/nfs/nfs2xdr.c